1. Field of the Invention
The present disclosure relates to a pharmaceutical composition for preventing or treating asthma including a Pistacia weinmannifolia (Pistacia weinmannifolia J. Poiss. Ex Franch) extract or a fraction thereof as an active ingredient, a health functional food for preventing or improving asthma including the extract or the fraction thereof, and use of the extract or the fraction thereof for the prevention or treatment of asthma.
2. Description of the Related Art
Asthma is a respiratory disease that causes difficulty in breathing, and about 3 million peoples of the Korean population suffer from asthma. Asthma is a disease accompanied by stridor, difficulty in breathing, sneezing, and cyanosis and chest pain due to a lack of oxygen in severe case. Recently, incidence of asthma is rapidly increasing due to air pollution, exposure to various chemicals, and westernized diets, and particularly, prevalence of asthma in children is increasing.
Asthma is a disease caused by TH2 (T-helper2) type-driven immune responses, which release interleukin-4, 5, 13, leading to recruitment and infiltration of a variety of inflammatory cells including eosinophils to the airways and tissues surrounding blood vessels. Various inflammatory mediators produced therefrom further increase inflammatory responses, resulting in an increase in mucus secretion and airway hyperresponsiveness.
With recent development of molecular biology, many attempts have been made to understand the roles of cytokines in asthma at a molecular level, and factors that influence this disease have been demonstrated one by one. Among the factors, nitric oxide (NO) is an inflammatory mediator, which acts as a defense by damaging pathogenic DNA, thereby maintaining homeostasis. NO is produced from L-arginine by three main isoforms of nitric oxide synthase (NOS), named nNOS (neuronal NOS), eNOS (endothelial NOS), and iNOS (inducible NOS). Excessive production of NO by iNOS of the isoforms is involved in various pathophysiological processes, including inflammation and cancer.
Until now, there have been developed many therapeutic agents for the treatment of asthma, such as steroids, bronchodilators, anti-inflammatory drugs, etc., but most of the therapeutic agents cause a wide range of side effects and thus use of the agents needs careful management. The most widely used inhaled corticosteroids exhibit excellent therapeutic effects, but long-term use thereof is known to cause adrenal suppression, reduction in bone density, growth retardation, complications in the eyes and skin, and increase in collagen synthesis, in proportion to the dose and period of use. Further, long-acting beta-2 agonists such as salmeterol and formoterol exhibit and prophylactic effect on asthma attack, but possibly leading to death in some patients. Due to such various side effects, careful consideration should be given to use of the existing asthma therapeutic agents. There is a continuous demand to develop a prophylactic or therapeutic agent for asthma with strong efficacy and fewer side effects.
Meanwhile, Pistacia weinmannifolia (Pistacia weinmannifolia J. Poiss, Ex Franch) is a plant widely found in Yunnan province of China and traditionally, it has been used in dysentery, enteritis, influenza, or headache. A previous research reported that two compounds isolated from this plant have a reactive oxygen species-scavenging ability (Zhao X. et al., Biochim Biophys Acta, 1725, 103-110, 2005). Besides this report, there is no report about an anti-asthma effect of a Pistacia weinmannifolia extract, a fraction thereof, or a compound isolated therefrom.
The present inventors have made many efforts to find out natural substances which are useful for the prevention or treatment of asthma without causing side effects in human, and as a result, they found that a Pistacia weinmannifolia extract or a fraction thereof suppresses nitric oxide production in animal cells, alleviates airway hyperresponsiveness in asthma-induced mouse models, and inhibits generation of reactive oxygen species in the airway without toxicity. The present inventors also found that the Pistacia weinmannifolia extract or the fraction thereof reduces the number of inflammatory cells and the level of interleukin in bronchoalveolar lavage fluid, inhibits IgE production in the serum and infiltration of inflammatory cells to the lung tissue, and reduces mucus secretion in the airway, and therefore, it is useful for the prevention or treatment of asthma, thereby completing the present invention.